U.S. patent number 9,291,138 [Application Number 13/666,791] was granted by the patent office on 2016-03-22 for fuel injector with injection control valve assembly.
This patent grant is currently assigned to CUMMINS INC.. The grantee listed for this patent is CUMMINS INC.. Invention is credited to Paul D. Free, Corydon E. Morris.
United States Patent |
9,291,138 |
Morris , et al. |
March 22, 2016 |
**Please see images for:
( Certificate of Correction ) ** |
Fuel injector with injection control valve assembly
Abstract
A fuel injector control valve is provided that includes a drain
circuit for directing the flow of fuel away from temperature
sensitive components of a fuel injector in which the fuel injector
control valve is positioned. The drain circuit includes at least
one portion that directs drain fuel axially inward or toward a fuel
injector orifice, and away from an actuator of the fuel
injector.
Inventors: |
Morris; Corydon E. (Columbus,
IN), Free; Paul D. (Hope, IN) |
Applicant: |
Name |
City |
State |
Country |
Type |
CUMMINS INC. |
Columbus |
IN |
US |
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Assignee: |
CUMMINS INC. (Columbus,
IN)
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Family
ID: |
48171094 |
Appl.
No.: |
13/666,791 |
Filed: |
November 1, 2012 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20130118451 A1 |
May 16, 2013 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61554117 |
Nov 1, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02M
63/0056 (20130101); F02M 63/0225 (20130101); F02M
47/027 (20130101); F02M 59/366 (20130101); F02M
51/061 (20130101); F02M 63/0215 (20130101); F02M
61/161 (20130101); F02M 55/002 (20130101) |
Current International
Class: |
F02M
57/00 (20060101); F02M 51/06 (20060101); F02M
47/02 (20060101); F02M 59/36 (20060101); F02M
55/00 (20060101); F02M 63/00 (20060101); F02M
61/16 (20060101); F02M 63/02 (20060101) |
Field of
Search: |
;123/445 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1 705 365 |
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Sep 2006 |
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EP |
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2 104 158 |
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Mar 1983 |
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GB |
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2 351 773 |
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Jan 2001 |
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GB |
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2008-115738 |
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May 2008 |
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JP |
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2010-209767 |
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Sep 2010 |
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JP |
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Other References
International Search Report and Written Opinion of the
International Searching Authority dated May 15, 2013 from
corresponding International Application No. PCT/US2012/063078.
cited by applicant.
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Primary Examiner: Huynh; Hai
Assistant Examiner: Laguarda; Gonzalo
Attorney, Agent or Firm: Faegre Baker Daniels LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of priority to U.S. Provisional
Patent Application No. 61/554,117, filed on Nov. 1, 2011, which is
hereby incorporated by reference in its entirety.
Claims
We claim:
1. A fuel injector for injecting fuel at high pressure into a
combustion chamber of an internal combustion engine, comprising: an
injector body including a longitudinal axis, an outer housing, an
injector cavity, a fuel delivery circuit, and an injector orifice
communicating with one end of the injector cavity to discharge fuel
from the fuel delivery circuit into the combustion chamber; a
nozzle valve element positioned in one end of the injector cavity
adjacent the injector orifice, the nozzle valve element movable
between an open position in which fuel may flow through the
injector orifice into the combustion chamber and a closed position
in which fuel flow through the injector orifice is blocked; a
control volume positioned to receive a pressurized supply of fuel;
a drain circuit positioned to drain fuel from the control volume
toward a low pressure drain, the drain circuit including an axially
inward flow passage extending the longitudinal axis toward the
injector orifice and positioned to receive drain fuel flow from the
control volume to direct drain fuel flow in a direction along the
longitudinal axis toward the injector orifice, and the drain
circuit including a transverse flow passage including a first end
and a second end; and an injection control valve assembly
positioned along the drain circuit to control fuel flow from the
control volume, the injection control valve assembly including a
valve housing having a valve cavity including an actuator, a fuel
injector control valve positioned within the valve cavity, a
control valve member positioned in the valve cavity to move between
an open position permitting flow through the drain circuit and a
closed position blocking flow through the drain circuit, and an
actuator positioned in the valve cavity to cause movement of the
control valve member between the open and closed positions, wherein
the first end of the transverse flow passage is in fluid
communication with the valve cavity and the second end of the
transverse flow passage is in fluid communication with the axially
inward flow passage and the first end, and the actuator includes a
stator and an armature operably connected to the control valve
member, the first end of the transverse flow passage opening into
the valve cavity radially adjacent a portion of the valve cavity
that is under a distal surface of the armature.
2. The fuel injector of claim 1, wherein the drain circuit further
includes an outlet port formed in the outer housing to direct fuel
outside of the injector body.
3. The fuel injector of claim 2, wherein the outlet port is
positioned along the longitudinal axis axially between the actuator
and the injector orifice.
4. The fuel injector of claim 2, wherein the outlet port is
positioned along the longitudinal axis axially between the control
valve member and the injector orifice.
5. The fuel injector of claim 1, the actuator including an armature
and wherein the transverse flow passage, including the first end
and the second end, is positioned along the longitudinal axis in a
location transversely adjacent the armature.
6. The fuel injector of claim 1, wherein the axially inward flow
passage is formed between an outer surface of the valve housing and
an inner surface of the outer housing.
7. The fuel injector of claim 1, wherein the fuel delivery circuit
includes a delivery passage extending axially within the valve
housing and the axially inward flow passage is located at a
position circumferentially adjacent the delivery passage.
8. A fuel injector for injecting fuel at high pressure into a
combustion chamber of an internal combustion engine, comprising: an
injector body including a longitudinal axis, an outer housing, an
injector cavity, and an injector orifice communicating with one end
of the injector cavity to discharge fuel into the combustion
chamber; a nozzle valve element positioned in one end of the
injector cavity adjacent the injector orifice, the nozzle valve
element movable between an open position in which fuel may flow
through the injector orifice into the combustion chamber and a
closed position in which fuel flow through the injector orifice is
blocked; a control volume positioned to receive a pressurized
supply of fuel; an injection control valve assembly positioned
along the drain circuit to control fuel flow from the control
volume, the injection control valve including a valve housing
having a valve cavity, a fuel injector control valve positioned
within the valve cavity, a control valve member positioned in the
valve cavity to move between an open position permitting fuel flow
through the drain circuit and a closed position blocking fuel flow
through the drain circuit, and an actuator positioned in the valve
cavity to cause movement of the control valve member between the
open and closed positions, the outlet port being positioned along
the longitudinal axis axially between the actuator and the injector
orifice; and a drain circuit positioned to drain fuel from the
control volume toward a low pressure drain, the drain circuit
including an outlet port formed in the outer housing to direct fuel
flowing from the control volume to outside of the injector body, an
axially inward flow passage formed between an exterior of the valve
housing and an interior of the outer housing, and a transverse flow
passage formed in the valve housing and including a first end in
fluid communication with the valve cavity and a second end in fluid
communication with the axially inward flow passage.
9. The fuel injector of claim 8, wherein the outlet port is
positioned along the longitudinal axis axially between the control
valve member and the injector orifice.
10. The fuel injector of claim 8, the actuator including an
armature and wherein the transverse flow passage, including the
first end and the second end, is positioned along the longitudinal
axis in a location transversely adjacent the armature.
11. The fuel injector of claim 8, wherein the actuator includes an
armature operably connected to the control valve member, the first
end of the transverse flow passage opening into the valve cavity
radially adjacent a portion of the valve cavity that is under a
distal surface of armature.
12. A fuel injector for injecting fuel at high pressure into a
combustion chamber of an internal combustion engine, comprising: an
injector body including a longitudinal axis, an outer housing, an
injector cavity, and an injector orifice communicating with one end
of the injector cavity to discharge fuel into the combustion
chamber; a nozzle valve element positioned in one end of the
injector cavity adjacent the injector orifice, the nozzle valve
element movable between an open position in which fuel may flow
through the injector orifice into the combustion chamber and a
closed position in which fuel flow through the injector orifice is
blocked; a control volume positioned to receive a pressurized
supply of fuel; a drain circuit positioned to drain fuel from the
control volume toward a low-pressure drain; and an injection
control valve positioned along the drain circuit to control fuel
flow from the control volume, the injection control valve including
a valve housing, a control valve member positioned in the valve
housing to move between an open position permitting flow through
the drain circuit and a closed position blocking flow through the
drain circuit, and an actuator positioned in the valve housing to
cause movement of the control valve member between the open and
closed positions, the actuator including a stator and an armature
operably connected to the control valve member, the valve housing
including a valve cavity containing the actuator, the drain circuit
further including a transverse flow passage formed in the valve
housing and extending perpendicularly to the longitudinal axis of
the injector body, the transverse flow passage including an
upstream end positioned transversely adjacent the armature in fluid
communication with the valve cavity and a downstream end in fluid
communication with the low pressure drain.
13. The fuel injector of claim 12, the drain circuit including an
outlet port formed in the outer housing to direct fuel flowing from
the control volume to outside of the injector body, the outlet port
being positioned along the longitudinal axis axially between the
actuator and the injector orifice.
14. The fuel injector of claim 12, wherein the outlet port is
positioned along the longitudinal axis axially between the control
valve member and the injector orifice.
15. An internal combustion engine, comprising: an engine body
including a mounting bore having an inner surface, a coolant
passage positioned adjacent the mounting bore to receive coolant
fluid, and a combustion chamber; a fuel injector received by the
inner surface of the mounting bore and including an injector body
including a longitudinal axis, an outer housing having an outer
surface positioned adjacent the inner surface, an injector cavity,
and an injector orifice communicating with one end of the injector
cavity to discharge fuel into the combustion chamber, the fuel
injector including a nozzle valve element positioned in one end of
the injector cavity adjacent the injector orifice, a control volume
positioned to receive a pressurized supply of fuel, a drain circuit
positioned within the fuel injector to drain fuel from the control
volume to outside the fuel injector, and an injection control valve
positioned within the injector body along the drain circuit to
control fuel flow from the control volume, the injection control
valve including a valve housing, a control valve member operable to
control the flow of fuel from the control volume through the drain
circuit, and an actuator positioned in the valve housing to cause
movement of the control valve member, and the valve housing
includes a valve cavity and the actuator is positioned within the
valve cavity; and an engine drain circuit including an axial drain
passage positioned between the inner surface of the mounting bore
and the fuel injector to receive fuel drain flow from the drain
circuit, the axial drain passage positioned in an overlapping
side-by-side relationship with the coolant passage for at least a
portion of the axial drain passage, and the axial drain passage is
axially positioned between the actuator and the injector orifice,
and the drain circuit further including a transverse flow passage
formed in the valve housing, the transverse flow passage including
a first end in fluid communication with the valve cavity and a
second end in fluid communication with the axial drain passage and
the first end.
16. The internal combustion engine of claim 15, the actuator
including a solenoid assembly for causing axial movement of the
control valve member along a longitudinal axis between said open
and closed positions, the solenoid assembly including a stator
including a first end and a second end positioned opposite said
first end, a coil positioned around said stator, a central aperture
extending through said stator from said first end to said second
end for receiving the control valve member and an armature
connectable to the control valve member and positioned a spaced
axial distance along said longitudinal axis from the coil.
17. The fuel injector of claim 15, wherein the drain circuit
further includes an outlet port formed in the outer housing to
direct fuel outside of the injector body and the outlet port is
positioned along the longitudinal axis axially between the actuator
and the injector orifice.
Description
TECHNICAL FIELD
This disclosure relates to control valves for fuel injectors.
BACKGROUND
A fuel injector control valve is critical to the operation of a
fuel injector because it causes a nozzle valve element of a fuel
injector to open and close, creating a fuel injection event. A
drain circuit is important to the operation of the fuel injector
control valve because the drain circuit is positioned to connect to
a control volume, and the control valve is opened and closed by
connecting and disconnecting the control volume to the drain
circuit.
SUMMARY
This disclosure provides a fuel injector for injecting fuel at high
pressure into a combustion chamber of an internal combustion
engine, comprising an injector body, a nozzle valve element, a
control volume, a drain circuit, and an injection control valve.
The injector body includes a longitudinal axis, an outer housing,
an injector cavity, a fuel delivery circuit, and an injector
orifice communicating with one end of the injector cavity to
discharge fuel from the fuel delivery circuit into the combustion
chamber. The nozzle valve element is positioned in one end of the
injector cavity adjacent the injector orifice and is movable
between an open position in which fuel may flow through the
injector orifice into the combustion chamber and a closed position
in which fuel flow through the injector orifice is blocked. The
control volume is positioned to receive a pressurized supply of
fuel. The drain circuit is positioned to drain fuel from the
control volume toward a low-pressure drain and the drain circuit
includes an axially inward flow passage extending along the
longitudinal axis toward the injector orifice. The axially inward
flow passage is positioned to receive drain fuel flow from the
control volume to direct drain fuel flow in a direction along the
longitudinal axis toward the injector orifice. The injection
control valve is positioned along the drain circuit to control fuel
flow from the control volume. The injection control valve includes
a valve housing, a control valve member, and an actuator positioned
in the valve housing to cause movement of the control valve member
between the open and closed positions. The control valve member is
positioned in the valve housing to move between an open position
permitting flow through the drain circuit and a closed position
blocking flow through the drain circuit.
This disclosure also provides a fuel injector for injecting fuel at
high pressure into a combustion chamber of an internal combustion
engine, comprising an injector body, a nozzle valve element, a
control volume, a drain circuit, and an injection control valve.
The injector body includes a longitudinal axis, an outer housing,
an injector cavity, and an injector orifice communicating with one
end of the injector cavity to discharge fuel into the combustion
chamber. The nozzle valve element is positioned in one end of the
injector cavity adjacent the injector orifice and is movable
between an open position in which fuel may flow through the
injector orifice into the combustion chamber and a closed position
in which fuel flow through the injector orifice is blocked. The
control volume is positioned to receive a pressurized supply of
fuel. The drain circuit is positioned to drain fuel from the
control volume toward a low-pressure drain. The drain circuit
includes an outlet port formed in the outer housing to direct fuel
flowing from the control volume to outside of the injector body.
The injection control valve is positioned along the drain circuit
to control fuel flow from the control volume. The injection control
valve includes a valve housing, a control valve member, and an
actuator positioned in the valve housing to cause movement of the
control valve member between the open and closed positions, the
outlet port being positioned along the longitudinal axis axially
between the actuator and the injector orifice. The control valve
member is positioned in the valve housing to move between an open
position permitting fuel flow through the drain circuit and a
closed position blocking fuel flow through the drain circuit.
This disclosure also provides a fuel injector for injection fuel at
high pressure into a combustion chamber of an internal combustion
engine, comprising an injector body, a nozzle valve element, a
control volume, a drain circuit, and an injection control valve.
The injector body includes a longitudinal axis, an outer housing,
an injector cavity, and an injector orifice communicating with one
end of the injector cavity to discharge fuel into the combustion
chamber. The nozzle valve element is positioned in one end of the
injector cavity adjacent the injector orifice, the nozzle valve
element is movable between an open position in which fuel may flow
through the injector orifice into the combustion chamber and a
closed position in which fuel flow through the injector orifice is
blocked. The control volume is positioned to receive a pressurized
supply of fuel. The drain circuit is positioned to drain fuel from
the control volume toward a low-pressure drain. The injection
control valve is positioned along the drain circuit to control fuel
flow from the control volume. The injection control valve includes
a valve housing, a control valve member, and an actuator positioned
in the valve housing to cause movement of the control valve member
between the open and closed positions. The control valve member is
positioned in the valve housing to move between an open position
permitting flow through the drain circuit and a closed position
blocking flow through the drain circuit. The actuator includes a
stator and an armature operably connected to the control valve
member. The valve housing includes a valve cavity containing the
actuator. The drain circuit further includes a transverse flow
passage formed in the valve housing, the transverse flow passage
including an upstream end positioned transversely adjacent the
armature in fluid communication with the valve cavity and a
downstream end in fluid communication with the low pressure
drain.
This disclosure also provides an internal combustion engine,
comprising an engine body, a fuel injector, and an engine drain
circuit. The engine body includes a mounting bore having an inner
surface sized to receive a fuel injector, a coolant passage
positioned adjacent the mounting bore to receive coolant fluid, and
a combustion chamber. The fuel injector is mounted in the mounting
bore and includes an injector body. The injector body includes a
longitudinal axis, an outer housing having an outer surface
positioned adjacent the inner surface, an injector cavity, and an
injector orifice communicating with one end of the injector cavity
to discharge fuel into the combustion chamber. The fuel injector
includes a nozzle valve element positioned in one end of the
injector cavity adjacent the injector orifice, a control volume
positioned to receive a pressurized supply of fuel, a drain circuit
positioned within the fuel injector to drain fuel from the control
volume to outside the fuel injector, and an injection control valve
positioned within the injector body along the drain circuit to
control fuel flow from the control volume. The injection control
valve includes a valve housing, a control valve member operable to
control the flow of fuel from the control volume through the drain
circuit, and an actuator positioned in the valve housing to cause
movement of the control valve member. The engine drain circuit
includes an axial drain passage positioned between the inner
surface of the mounting bore and the fuel injector to receive fuel
drain flow from the drain circuit. The axial drain passage is
positioned in an overlapping side-by-side relationship with the
coolant passage for at least a portion of the axial drain passage,
and the axial drain passage is axially positioned between the
actuator and the injector orifice.
Advantages and features of the embodiments of this disclosure will
become more apparent from the following detailed description of
exemplary embodiments when viewed in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a portion of an internal
combustion engine.
FIG. 2 is a cross-sectional view of a portion of the internal
combustion engine of FIG. 1, showing a first exemplary embodiment
of the present disclosure.
FIG. 3 is a perspective view of a control valve cartridge assembly
of FIG. 2.
FIG. 4 is a cross-sectional view similar to FIG. 2, showing a
second exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION
Referring to FIG. 1, a portion of an internal combustion engine is
shown generally indicated at 10. Engine 10 includes an engine body
12, which includes an engine block (not shown) and a cylinder head
14 attached to the engine block. Engine 10 also includes a fuel
system 16 that includes one or more fuel injectors 18, a fuel pump,
a fuel accumulator, valves, and other elements (not shown) that
connect to fuel injector 18.
Referring to FIGS. 1-3, fuel injector 18 includes an injector body
20, a nozzle valve element 22, a control volume 24, a drain circuit
26, and an injection control valve assembly 28.
Applicants recognized that one challenge with drain circuits is
that they carry hot fuel and the compact nature of fuel injectors
causes the hot fuel to flow in undesirable areas, such as in
proximity to an actuator of the fuel injector, which contains
temperature sensitive components. While this configuration may
provide design simplicity, this configuration also subjects
temperature sensitive components such as the insulation of a
solenoid coil and potting material around the solenoid coil to
undesirably high temperatures. This issue is especially true in
injectors having a servo-controlled nozzle valve element, such as
in the exemplary embodiment of the present disclosure, wherein a
control volume positioned adjacent an outer end of the nozzle valve
element directs hot fuel to the drain circuit for draining fuel
from the control volume to a low-pressure drain, and an injection
control valve positioned along the drain circuit controls movement
of the nozzle valve element between open and closed positions.
Opening of the injection control valve causes a reduction in the
fuel pressure in the control volume resulting in a pressure
differential, which forces the nozzle valve element open, and
closing of the injection control valve causes an increase in the
control volume pressure and closing of the nozzle valve element. As
will be seen, drain circuit 26 and injection control valve assembly
28 in accordance with a first exemplary embodiment of the present
disclosure include features that reduce heat transfer from fuel
flowing through drain circuit 26 to temperature sensitive portions
of fuel injector 18, improving the life and performance of fuel
injector 18.
Engine body 12 includes a mounting bore 30 formed by an inner wall
or surface 32, sized to receive fuel injector 18, and a clamp
assembly 46 for securing fuel injector 18 in mounting bore 30.
Engine body 12 also includes a combustion chamber 34 and one or
more coolant passages 36, 38, 40, 42, 44 and 45 arranged about
mounting bore 30 and along combustion chamber 34 to provide cooling
to fuel injector 18 and components surrounding or adjacent
combustion chamber 34. Combustion chamber 34, only a portion of
which is shown in FIG. 1, is positioned in a known manner in engine
body 12, between cylinder head 14 and the engine block (not shown).
At least a portion of at least one coolant passage, e.g., coolant
passages 36 and 42, extend in a longitudinal direction in a portion
of cylinder head 14 alongside or adjacent mounting bore 30. At
least a portion of at least one coolant passage, e.g., coolant
passages 38 and 44, extend generally transverse to mounting bore 30
in a portion of cylinder head 14 that is at least partially
alongside combustion chamber 34. Engine body 12 further includes a
low-pressure engine drain circuit 94 including an engine drain
passage 93 connected to a low-pressure drain, e.g., an engine fuel
sump.
Throughout this specification, inwardly, distal, and near are
longitudinally in the direction of combustion chamber 34.
Outwardly, proximate, and far are longitudinally away from the
direction of combustion chamber 34.
Injector body 20 includes a longitudinal axis 48 extending along
the length of injector body 20, an upper body or barrel portion 49,
an outer housing or retainer 50, a nozzle housing 57 positioned in
outer housing 50, and an injector cavity 52 located within nozzle
housing 57. Injector body 20 further includes a fuel delivery
circuit 54, one or more injector orifices 56 positioned at a distal
end of outer housing 50, and an upper cavity 137 positioned between
control valve assembly 28 and barrel portion 49. Injector
orifice(s) 56 communicate with one end of injector cavity 52 to
discharge fuel from fuel delivery circuit 54 into combustion
chamber 34. In addition to locating the elements of fuel injector
18, outer housing 50 includes an interior surface 53, an exterior
surface 55, and a transversely or radially extending outlet port 51
positioned between interior surface 53 and exterior surface 55.
Nozzle valve element 22 is positioned in one end of injector cavity
52 adjacent injector orifice 56. Nozzle valve element 22 is movable
between an open position in which fuel may flow through injector
orifice 56 into combustion chamber 34 and a closed position in
which fuel flow through injector orifice 56 is blocked.
Nozzle valve element 22 extends into a nozzle element cavity 58
formed within a nozzle element guide 60. Control volume 24 is
formed between an end of nozzle valve element 22 and an interior of
nozzle element guide 60. Nozzle element guide 60 includes a
proximal cap or end portion 62 and a control volume plug 64. End
portion 62 of nozzle element guide 60 forms control volume 24 when
end portion 62 and nozzle element guide 60 are mounted in injector
cavity 52. Control volume plug 64 is mounted within nozzle element
cavity 58 in a location adjacent to end portion 62. End portion 62
includes an end portion passage 63 that extends longitudinally
through end portion 62 and one or more transverse end portion
passages 67. Control volume plug 64 includes a plurality of
longitudinal plug channels or passages 66 located about a periphery
of control volume plug 64 and a longitudinally extending central
passage 68. Control volume 24 receives high-pressure fuel from
injector cavity 52 by way of transverse end portion passage 67 and
plug passage 66. Central passage 68 is positioned to connect
control volume 24 to end portion passage 63.
The pressure of fuel in control volume 24 determines whether nozzle
valve element 22 is in an open position or a closed position, which
is further determined by injection control valve assembly 28,
described in more detail hereinbelow. When nozzle valve element 22
is positioned in injector cavity 52, nozzle element guide 60, and
more specifically, end portion 62 of nozzle element guide 60, is
positioned longitudinally between nozzle valve element 22 and
injection control valve assembly 28. Other servo controlled nozzle
valve assemblies may be used, such as those disclosed in U.S. Pat.
No. 6,293,254, the entire content of which is hereby incorporated
by reference.
A flow limiter assembly 72 may be positioned at a proximate end of
fuel injector 18 and flow limiter assembly 72 may include a limiter
outer housing 74 and a flow limiter sub-assembly 76. An inlet fuel
circuit 70 extends through limiter outer housing 74 of flow limiter
assembly 72 to connect fuel system 16 with fuel delivery circuit
54. Limiter outer housing 74 includes a high-pressure inlet 78, one
or more bosses 80, and a housing recess or bore portion 82 into
which a portion of flow limiter sub-assembly 76 extends.
High-pressure inlet 78 may be connected to a fuel rail or
accumulator (not shown), or may be a part of a daisy chain
arrangement wherein other fuel injectors may be connected via
appropriate high-pressure lines to, for example, bosses 80
integrally formed in limiter outer housing 74, either upstream or
downstream of high-pressure inlet 78. Inlet fuel circuit 70 extends
from high-pressure inlet 78 through limiter outer housing 74 and
through flow limiter sub-assembly 76 to connect with fuel delivery
circuit 54. Flow limiter assembly 72 may include a pulsation
dampener 84 positioned along inlet fuel circuit 70, which serves to
reduce transmission of pulsation waves, caused by injection events,
between fuel injectors.
Fuel delivery circuit 54 is positioned to connect high-pressure
fuel from inlet fuel circuit 70 to injector cavity 52 and control
volume 24. Fuel delivery circuit 54 includes a plurality of
longitudinally extending fuel delivery passages 86 extending
through injection control valve assembly 28 to provide
high-pressure fuel to injector cavity 52 and control volume 24.
Injection control valve assembly 28 is positioned along drain
circuit 26 and includes a valve housing 88 having a valve cavity 96
formed by a valve housing interior surface 91, and a fuel injector
control valve 95 positioned within valve cavity 96. Injector
control valve 95 includes a control valve member 90 and an actuator
92 positioned in valve housing 88 to cause movement of control
valve member 90 between the open and closed positions. Control
valve member 90 is positioned in valve cavity 96 to move
reciprocally between an open position permitting flow through drain
circuit 26 and a closed position blocking flow through drain
circuit 26. Actuator 92 includes a solenoid assembly 108 that
includes a stator housing 109 having a first end 112 and a second
end 114, a stator 110 positioned in stator housing 109, a coil 116
positioned circumferentially in and around stator 110, and an
armature 106 operably connected to control valve member 90. Stator
housing 109 includes a stator housing exterior surface 111, a
central aperture, bore or core 118 extending through stator housing
109 from first end 112 to second end 114, and a transversely
extending stator passage 117. Central aperture 118 includes a
spring cavity 125 and is positioned to receive control valve member
90. An annular stator housing passage 113 is formed between valve
housing interior surface 91 and exterior surface 111 of stator
housing 109. In the exemplary embodiment, annular stator housing
passage 113 is formed on exterior surface 111 of stator housing
109. An annular gap 127 exists between exterior surface 111 of
stator housing 109 and valve housing interior surface 91. Annular
gap 127 permits air to travel between stator housing 109 and valve
housing 88 to upper cavity 137 where the air remains or is
dissolved into solution with the drain fuel over time.
Injection control valve assembly 28 also includes a seat portion
119, a seat retainer 120, and an adjusting ring 121 positioned in a
distal end of valve cavity 96. Seat portion 119 includes a control
valve seat 122 and a longitudinally extending seat portion passage
124. Adjusting ring 121 includes a plurality of radially or
transversely extending adjusting ring passages 126. An annular
groove 123 may be formed between an exterior of adjusting ring 121
and interior surface 91 of valve housing 88. In the exemplary
embodiment, annular groove 123 is formed on an exterior of
adjusting ring 121. Adjusting ring 121 is sized, positioned, and
adjusted to space armature 106 an axial distance from stator 110
and coil 116 along longitudinal axis 48.
As best seen in FIG. 3, injection control valve assembly 28 may
also include a cover plate 132, which includes openings 133,
retainers 134, and central opening 135. Retainers 134 include
threads 136 formed at a first or distal end of retainers 134, an
interface portion 140, and a pin portion 142. Valve housing 88
includes threaded recesses 138 having threads that mate with
threads 136. The first or distal end of retainers 134 extend
through openings 133 formed in cover plate 132 to engage with
threaded recesses 138. Interface portion 140 is shaped to mate with
an adjusting tool (not shown) that permits retainers 134 to be
tightened securely to valve housing 88. Once cover plate 132 is
secured to valve housing 88 by retainers 134, the components
positioned in valve cavity 96, including control valve member 90,
actuator 92, seat portion 119, seat retainer 120, and adjusting
ring 121, are secured within valve housing 88 to form a
self-contained valve cartridge assembly 146. Valve cartridge
assembly 146 may include a bias spring 144 positioned between
stator housing 109 and cover plate 132 to position the fixed
elements of valve cartridge assembly 146 in an abutting
relationship when cover plate 132 is secured to valve housing 88.
Because injection control valve cartridge assembly 146 is formed as
a single integrated unit or a complete assembly, it may be easily
installed or inserted within outer housing 50. Barrel portion 49
contains recesses (not shown) that mate with pin portion 142 to
provide proper orientation of barrel 49 with cartridge assembly
146.
Valve housing 88 includes a transversely or radially extending flow
passage 98 connecting valve cavity 96 to an exterior of valve
housing 88, a longitudinally extending first drain passage 100, and
one or more relief passages 99. A longitudinally or axially
inwardly extending flow passage 102 is provided to connect
transversely extending passage 98 to outlet port 51. Inward flow
passage 102 is formed between an exterior surface 89 of valve
housing 88 and interior surface 53 of outer housing 50. In the
exemplary embodiment, flow passage 102 includes an axial groove 103
formed in valve housing 88. Valve housing 88 also includes axially
extending fuel delivery passage(s) 86, which are part of fuel
delivery circuit 54. Axially inward flow passage 102 is positioned
circumferentially adjacent to at least one fuel delivery passage
86, and may be positioned circumferentially adjacent to two fuel
delivery passages 86. Transverse flow passage 98 is positioned a
spaced circumferential distance from axially extending fuel
delivery passages 86. Thus, transverse flow passage 98 extends
between two adjacent fuel delivery passages 86, as best seen in
FIG. 3. Transverse flow passage 98 is also positioned
longitudinally in a location that is transversely adjacent to
actuator 106, and, more specifically, is transversely or radially
adjacent to the portion of valve cavity 96 that is adjacent
armature 106, and more specifically, a distal surface 107 of
armature 106. Because fuel injector 18 is typically operated in the
orientation shown in FIG. 1, transverse flow passage 98 is also
adjacent a portion of valve cavity 96 that is below or under distal
surface 107 of armature 106. First drain passage 100 is positioned
to connect injector cavity 52 to valve cavity 96.
Drain circuit 26 extends from control volume 24 through injection
control valve assembly 28, through outer housing 50 into mounting
bore 30, to engine drain passage 93 of low-pressure engine drain
circuit 94. More specifically, drain circuit 26 includes central
passage 68, end portion passage 63, first drain passage 100, seat
portion passage 124, valve cavity 96, adjusting ring passage 126,
annular groove 123, transverse flow passage 98, axially inward flow
passage 102, and outlet port 51. Outlet port 51 is positioned
longitudinally between injector orifice 56 and actuator 92, and may
be positioned longitudinally between injector orifice 56 and
control valve member 90. When fuel injector 18 is positioned in
mounting bore 30, outer or exterior surface 55 of outer housing 50
is positioned adjacent to inner surface 32 of mounting bore 30, and
an axially extending drain passage 130 is formed by exterior
surface 55 of outer housing 50 and inner surface 32 of mounting
bore 30. As described further hereinbelow, axial drain passage 130
is included as a part of drain circuit 26. Axial drain passage 130
overlaps at least one engine body coolant passage, e.g., coolant
passage 45, in an axial direction, which means that axial drain
passage 130 and coolant passage 45 are side-by-side or radially
adjacent for at least a portion of axial drain passage 130. Axial
drain passage 130 is positioned longitudinally between actuator 92
and injector orifice 56. More specifically, axial drain passage 130
extends longitudinally from outlet port 51 to a location adjacent
engine drain passage 93 to permit fluid communication between
outlet port 51 and engine drain passage 93.
When injector control valve 95 is energized by an engine control
system (not shown), actuator 92 is operable to move armature 106
longitudinally toward stator 110. Movement of armature 106 causes
control valve member 90 to move longitudinally away from control
valve seat 122, which causes drain circuit 26 to be connected with
control volume 64. Fuel is immediately able to flow outwardly
through central passage 68, end portion passage 63, first drain
passage 100, and seat portion passage 124. Fuel then flows between
control valve member 90 and control valve seat 122 and into valve
cavity 96. The fuel in valve cavity 96 continues to flow
longitudinally outward toward and then transversely through
adjusting ring passage 126. Because adjusting ring 121 is movable
to establish the position of stator housing 109, adjusting ring
passage 126 may be misaligned with transverse flow passage 98.
Annular groove 123 permits fuel to flow from adjusting ring passage
126 to transverse flow passage 98, regardless of the position of
adjusting ring passages 126 with respect to transverse flow passage
98. Transverse flow passage 98 is in fluid communication with valve
cavity 96 at an upstream or first end and axially inward flow
passage 102, and thus engine drain passage 93 of low-pressure drain
94, at a downstream or second end, receiving fuel flow from valve
cavity 96 by way of adjusting ring passage 126. The first end of
transverse flow passage 98 opens into valve cavity 96 in a location
that is radially adjacent to armature 106, and more specifically,
to distal surface 107 of a transverse portion 115 of armature 106.
The fuel flows radially or transversely through adjusting ring
passage 126, into annular groove 123, and into transversely
extending passage 98, moving from valve cavity 96 into axially
inward flow passage 102.
Because drain fuel flows directly from valve cavity 96 to axially
inward flow passage 102 by way of transversely extending passage
98, the hot drain fuel is directed away from solenoid assembly 108,
reducing the heat transferred from the hot drain fuel to solenoid
assembly 108. In addition to reducing heat transfer to solenoid
assembly 108, location of transversely extending passage 98 is
advantageous in that the drain fuel is able to carry air and debris
away from components such as armature 106 and stator 110,
potentially improving the reliability and durability of these
components. Additionally, since transverse flow passage 98 is
positioned circumferentially adjacent or between fluid delivery
passage 86, there is some heat transfer from the hot drain fuel to
the cooler fuel in fluid delivery passages 86, providing cooling to
the hot drain fuel. Once in axially inward flow passage 102, fuel
flows longitudinally or axially inwardly in a direction that is
toward outlet port 51, where the fuel flows into outlet port 51.
Axial drain passage 130 receives the drain fuel from outlet port
51, directing the drain fuel longitudinally or axially inwardly in
a direction that is toward the distal end of fuel injector 18,
which is toward injector orifices 56. The fuel then flows into
engine drain passage 93 of low-pressure engine drain circuit 94.
Thus, drain circuit 26 is positioned to receive drain fuel from
control volume 24 and to drain the fuel toward low-pressure engine
drain circuit 94.
With connection of control volume 24 to engine drain circuit 94,
fuel pressure in control volume 24 is significantly reduced in
comparison to fuel pressure in injector cavity 52. The pressure on
the distal end of nozzle valve element 22 is significantly greater
than the pressure on the proximate end of nozzle valve element 22,
forcing nozzle valve element 22 longitudinally away from injector
orifices 56, and permitting high-pressure fuel to flow from
injector cavity 52 into combustion chamber 34. When actuator 92 is
de-energized, control valve member 90 is biased by springs to cause
injector control valve 95 to close. When injector control valve 95
is closed, pressure builds in control volume 24, causing, in
combination with a nozzle element bias spring 128, nozzle valve
element 22 to move longitudinally toward injector orifices 56,
closing or blocking injector orifices 56.
The benefit of drain circuit 26 is that hot fuel flowing through
drain circuit 26 is moved out from valve cavity 96 prior to
reaching temperature sensitive solenoid assembly 108, and
especially temperature sensitive coil 116, which includes
temperature sensitive insulation and potting material. In previous
fuel injector designs, hot fuel in the drain circuit flows past the
actuator, including electrical components such as coil 116,
subjecting these components to unnecessary and potentially damaging
heat. By redirecting drain flow away from actuator 92, the life and
reliability of actuator 92, and particularly coil 116, may be
improved, resulting in improved life for fuel injector 18.
Additionally, since drain circuit 26 extends past coolant passage
45, the fuel flowing through drain circuit 26 is beneficially
cooled prior to returning to fuel system 16.
During operation, control valve member 90 moves up and down,
causing a pumping action to occur in spring cavity 125. Stator
passage 117 is positioned to connect spring cavity 125 to annular
gap 127 and to one or more relief passages 99 formed in valve
housing 88, thus providing an unrestricted venting of spring cavity
125, which allows unencumbered movement of control valve member
90.
Referring to FIG. 4, a second exemplary embodiment fuel injector
218 in accordance with the present disclosure is shown. Items in
this embodiment that have the same number in the first exemplary
embodiment are as described in the first exemplary embodiment. Fuel
injector 218 is positioned in a mounting bore 330 formed in a
cylinder head 214 of an engine body 212, which are functionally
similar to mounting bore 30, engine body 12, and cylinder head 14,
but are structurally different from the latter elements. Fuel
injector 218 includes an injector body 320, nozzle valve element
22, control volume 24, a drain circuit 226, and an injection
control valve assembly 228. As will be seen, drain circuit 226 and
injection control valve assembly 228 in accordance with the second
exemplary embodiment of the present disclosure include features
that reduce heat transfer from fuel flowing through drain circuit
226 to temperature sensitive portions of fuel injector 218,
improving the life and performance of fuel injector 218. Injection
control valve assembly 228 may be configured as an integrated or
self-contained cartridge assembly, as described in the previous
embodiment.
Engine body 212 includes mounting bore 330 formed by an inner wall
or surface 332, sized to receive fuel injector 218. Engine body 212
also includes at least one coolant passage 245 arranged about
mounting bore 330 to provide cooling to fuel injector 218. Engine
body 212 further includes a low-pressure engine drain circuit 294
including an engine drain passage 93 connected to a low-pressure
drain, e.g., an engine fuel sump.
Injector body 320 includes a longitudinal axis 248 extending along
the length of injector body 320, an outer housing or retainer 150,
and injector cavity 52 located within outer housing 150. Though not
shown in FIG. 4, fuel injector 218 includes injector orifices 56
positioned at a distal end of outer housing 150, as shown for fuel
injector 18 in FIG. 2. Fuel injector 218 also includes fuel
delivery circuit 54, as shown in FIG. 1. Injector orifice(s) 56
communicate with one end of injector cavity 52 to discharge fuel
from fuel delivery circuit 54 into combustion chamber 34. In
addition to locating the elements of fuel injector 218, outer
housing 150 includes an interior surface 253, an exterior surface
255, and a transversely or radially extending outlet port 251
positioned between interior surface 253 and exterior surface
255.
Nozzle valve element 22 is as described in the first embodiment,
and is described in this embodiment only to the extent necessary
for clarity. Nozzle valve element 22 extends into nozzle element
cavity 58 formed within nozzle element guide 60. Control volume 24
is formed between the end of nozzle valve element 22 and the
interior of nozzle element guide 60. Nozzle element guide 60 is as
described in the first exemplary embodiment.
Fuel delivery circuit 54 is positioned to connect high-pressure
fuel from inlet fuel circuit 70 to injector cavity 52 and control
volume 24. Fuel delivery circuit 54 includes a plurality of
longitudinally or axially extending fuel delivery passages 86
extending through injection control valve assembly 228 to provide
high-pressure fuel to control volume 24.
Injection control valve assembly 228 is positioned along drain
circuit 226 and includes a valve housing 188 having a valve cavity
296 formed by a valve housing interior surface 291, and a fuel
injector control valve 295. Injector control valve 295 includes a
control valve member 90 and actuator 92 positioned in valve housing
188 to cause movement of control valve member 90 between the open
and closed positions. Control valve member 90 is positioned in
valve cavity 296 to move reciprocally between an open position
permitting flow through drain circuit 226 and a closed position
blocking flow through drain circuit 226. Actuator 92 includes
armature 106 operably connected to control valve member 90,
solenoid assembly 108 that includes stator housing 109 having first
end 112 and second end 114, stator 110 positioned in stator housing
109, and coil 116 positioned circumferentially in stator 110.
Stator housing 109 is as described in the first embodiment.
Injection control valve assembly 228 includes seat portion 119, a
seat retainer 300, and an adjusting ring 302 positioned in a distal
end of valve cavity 296. Seat portion 119 includes control valve
seat 122 and longitudinally extending seat portion passage 124.
Seat retainer 300 includes a plurality of radially or transversely
extending retainer passages 326. An annular groove or passage 292
may be formed between an exterior of seat retainer 300 and valve
housing interior surface 291. In the exemplary embodiment, annular
groove 292 is formed in valve housing 188. Adjusting ring 302 is
sized, positioned, and adjusted to space armature 106 an axial
distance from stator 110 and coil 116 along longitudinal axis
248.
Valve housing 188 includes a transversely or radially extending
passage 298 connecting valve cavity 296 to an exterior of valve
housing 188, longitudinally extending first drain passage 100, and
one or more relief passages 99. A longitudinally inwardly extending
flow passage 202 is provided to connect transversely extending
passage 298 to outlet port 251. Inward flow passage 202 is formed
between an exterior surface 189 of valve housing 188 and interior
surface 253 of outer housing 150. In the second exemplary
embodiment, flow passage 202 includes an axial groove 203 formed in
valve housing 188. Valve housing 188 also includes axially
extending fuel delivery passage(s) 86, which are part of fuel
delivery circuit 54. Axially inward flow passage 202 is positioned
circumferentially adjacent to at least one fuel delivery passage
86, and may be positioned circumferentially adjacent to two fuel
delivery passages 86. Transverse flow passage 298 is longitudinally
in a location that is transversely or radially adjacent to seat
portion 119 and to a distal end of seat retainer 300, and is
positioned a spaced circumferential distance from axially extending
fuel delivery passages 86. Thus, transverse flow passage 298
extends between two adjacent fuel delivery passages 86, similar to
the configuration shown for transverse flow passage 98 shown in
FIG. 3. First drain passage 100 is positioned to connect injector
cavity 52 to valve cavity 296.
Drain circuit 226 extends from control volume 24 through injection
control valve assembly 228, through outer housing 150 into mounting
bore 330, to low-pressure engine drain circuit 294. More
specifically, drain circuit 226 includes central passage 68, end
portion passage 63, first drain passage 100, seat portion passage
124, valve cavity 296, retainer passages 326, annular groove or
passage 292, transverse flow passage 298, axially inward flow
passage 202, and outlet port 251. Outlet port 251 is positioned in
a location longitudinally between injector orifice 56 and actuator
92. When fuel injector 218 is positioned in mounting bore 330,
outer or exterior surface 255 of outer housing 150 is positioned
adjacent to inner surface 332 of mounting bore 330, and an axially
extending drain passage 230 is formed by exterior surface 255 of
outer housing 150 and inner surface 332 of mounting bore 330. As
described further hereinbelow, axial drain passage 230 is included
as a part of drain circuit 226. Axial drain passage 230 overlaps at
least one engine body coolant passage, e.g., coolant passage 245,
in an axial direction, which means that axial drain passage 230 and
coolant passage 245 are side-by-side or adjacent for at least a
portion of axial drain passage 230. Axial drain passage 230 extends
from a position that is longitudinally between actuator 92 and
injector orifice 56 outwardly to engine drain passage 293.
When injector control valve 295 is energized by an engine control
system (not shown), actuator 92 is operable to move armature 106
and thus control valve member 90 longitudinally toward stator 110.
Movement of control valve member 90 longitudinally toward stator
110 and coil 116 is simultaneously movement away from control valve
seat 122, which connects drain circuit 226 with control volume 64.
Fuel is immediately able to flow outwardly through central passage
68, end portion passage 63, first drain passage 100, and seat
portion passage 124. Fuel then flows between control valve member
90 and control valve seat 122 and into valve cavity 296. The fuel
in valve cavity 296 continues to flow longitudinally outward toward
and through retainer passages 326. Because seat retainer 300 is
movable to secure seat portion 119, retainer passages 326 may be
misaligned with transverse flow passage 226. Annular groove 292
permits fuel to flow from retainer passages 326 to transverse flow
passage 298, regardless of the position of retainer passages 326
with respect to transverse flow passage 298. Transverse flow
passage 298 is in fluid communication with valve cavity 296 at an
upstream or first end and axially inward flow passage 202 at a
downstream or second end, and thus engine drain passage 293 of
low-pressure drain circuit 294, receiving fuel flow from valve
cavity 296 by way of retainer passages 326. The first end of
transverse flow passage 298 opens into valve cavity 296 in a
location that is radially or transversely adjacent the distal end
of seat retainer 300 and seat portion 119. The fuel flows radially
or transversely through retainer passages 326 and into transversely
extending passage 298, moving from valve cavity 296 into axially
inward flow passage 202. Once in axially inward flow passage 202,
fuel flows longitudinally or axially inwardly in a direction that
is toward outlet port 251, flowing through outlet port 251 into
axial drain passage 230. Once in axial drain passage 230, fuel
flows longitudinally or axially outwardly in a direction that is
away from the distal end of fuel injector 218, which is away from
injector orifices 56. The fuel then flows into engine drain passage
293 of low-pressure engine drain circuit 294. As with the previous
embodiment, the flow of fuel is away from the temperature sensitive
components of solenoid assembly 108.
With connection of control volume 24 to engine drain circuit 294,
fuel pressure in control volume 24 is significantly reduced in
comparison to fuel pressure in injector cavity 52. The pressure on
the distal end of nozzle valve element 22 is significantly greater
than the pressure on the proximate end of nozzle valve element 22,
forcing nozzle valve element 22 longitudinally away from injector
orifices 56, and permitting high-pressure fuel to flow from
injector cavity 52 into combustion chamber 34. When actuator 92 is
de-energized, control valve member 90 is biased by springs to cause
injection control valve assembly 228 to close. When injection
control valve assembly 228 is closed, pressure builds in control
volume 24, causing, in combination with a nozzle element bias
spring 128, nozzle valve element 22 to move longitudinally toward
injector orifices 56, closing or blocking injector orifices 56.
The benefit of drain circuit 226 is that hot fuel flowing through
drain circuit 226 is moved out from valve cavity 296 prior to
reaching temperature sensitive actuator 92, and especially
temperature sensitive coil 116. In previous fuel injector designs,
hot fuel in the drain circuit flows past the stator, including
electrical components such as coil 116, subjecting these components
to unnecessary and potentially damaging heat. By redirecting drain
flow away from solenoid assembly 108, the life and reliability of
solenoid assembly 108, and particularly coil 116, may be improved,
resulting in improved life for fuel injector 218. Additionally,
since drain circuit 226 extends past fuel delivery passages 86 and
coolant passage 245, the fuel flowing through drain circuit 226 is
beneficially cooled prior to returning to fuel system 16.
While various embodiments of the disclosure have been shown and
described, it is understood that these embodiments are not limited
thereto. The embodiments may be changed, modified and further
applied by those skilled in the art. Therefore, these embodiments
are not limited to the detail shown and described previously, but
also include all such changes and modifications.
* * * * *